Please take into consideration sizes have changed over the decades.. I'm not sure if an infants 18 months size in the 1980s is the same as it is now. See photos of measurements. Measurements listed below are estimates. This was mine as a child so the era is either late 1970s or early 1980s. I don't remember wearing it but put it on a lot of my dolls. The information on the tags has faded to where you can barely read anything but you can make out the 18M for 18 months.

Measurements again are estimates. I do my best but I'm far from perfect.

From armpit to armpit 9".

Center of neckline to bottom 11".

Top of shoulder to bottom 12" - 12.5" approx.

Good condition for age. No holes, or major discolorations. Very clean. There might be minor fading of the pink around the neckline.